Controllers and Methods of Control of Water Heaters

• US 20150039153A1
• Filed: 03/04/2014
• Published: 02/05/2015
• Est. Priority Date: 08/02/2013
• Status: Active Grant

• Current Assignee: Copeland Comfort Control LP (Emerson Electric Company)
• Original Assignee: Emerson Electric Company
• Inventors: Taware, Sachin B., Kulkarni, Amol N.
• Granted Patent: US 9,651,955 B2
• Time in Patent Office: Days
• US Class Current: 700/300
• CPC Class Codes: F24H 15/156 Reducing the quantity of energy consumed; Increasing efficiency
• CPC Class Codes: F24H 15/174 Supplying heated water with desired temperature or desired range of temperature
• CPC Class Codes: F24H 15/176 Improving or maintaining comfort of users
• CPC Class Codes: F24H 15/212 Temperature of the water
• CPC Class Codes: F24H 15/281 Input from user
• CPC Class Codes: F24H 15/36 of burners
• CPC Class Codes: F24H 15/37 of electric heaters
• CPC Class Codes: F24H 15/486 using timers
• CPC Class Codes: F24H 9/2014 using electrical energy supply
• CPC Class Codes: F24H 9/2035 using fluid fuel
• CPC Class Codes: G05D 23/1902 characterised by the use of a variable reference value

Abstract

A water heater that is controlled by a plurality of offsets depending on at least one of predicted current usage of the water heater and preset user set point temperature results in energy saving without affecting user comfort and eliminates the need for additional hardware. The average temperature of the water is lower than in the case where a single preset offset is adjusted, thereby resulting in energy saving.

Claims

1. A controller for a water heater, the controller comprising:

a base repository comprising continually learned usage of the water heater including learned number of heat calls generated in a predetermined time duration and learned heat call ON time;

a tracking repository comprising current usage of the water heater including currently tracked number of heat calls made in the predetermined time duration and currently tracked heat call ON time;

a comparator adapted to compare the current usage of the water heater with the learned usage of the water heater to predict the current usage of the water heater as any one of High, Medium, Low, and No usage;

first setting means to set a user set point temperature depending on user comfort;

second setting means to set a plurality of offsets comprising a first preset offset defining a temperature at which power is enabled when the High usage of the water heater is detected and at least one alternate offset defining a temperature at which power is enabled when at least one of the Medium, the Low, and the No usage of the water heater is detected;

a timer adapted to set a predetermined time delay between the plurality of offsets; and

a processor adapted to generate a heat call when the temperature of the water in the water heater drops from the preset user set point to at least one of the plurality of offsets, depending on at least one of the predicted current usage of the water heater and the preset user set point temperature.

2. The controller for a water heater of claim 1, further comprising:

an override means adapted to override the at least one alternate offset; and

a sensor adapted to sense rate of change of temperature of water.

3. A water heater comprising the controller of claim 1.

4. A gas based water heater comprising the controller of claim 1.

5. An electric based water heater comprising the controller of claim 1.

6. A method for controlling heat call generated in a water heater, the method comprising:

continually tracking current usage of the water heater including currently tracked number of heat calls made in a predetermined time duration and currently tracked heat call ON time;

storing learned usage of the water heater including learned number of heat calls generated in the predetermined time duration and learned heat call ON time;

comparing the current usage of the water heater with the learned usage of the water heater to predict the current usage of the water heater as any one of High, Medium, Low, and No usage;

presetting a user set point temperature depending on user comfort;

presetting a plurality of offsets comprising a first preset offset defining a temperature at which power is enabled when the High usage of the water heater is detected and at least one alternate offset defining a temperature at which power is enabled when at least one of the Medium, the Low, and the No usage of the water heater is detected;

setting a predetermined time delay between the plurality of offsets; and

generating a heat call when the temperature of the water in the water heater drops from the preset user set point to at least one of the plurality of offsets, depending on at least one of the predicted current usage of the water heater and the preset user set point temperature.

7. The method of claim 6, further comprising:

detecting rate of change of temperature of the water; and

overriding the at least one alternate offset.

8. The method of claim 6, wherein presetting a plurality of offsets includes incrementing the first preset offset by a predetermined offset adjustment to define the at least one alternate offset.

9. The method of claim 6, wherein generating a heat call facilitates reducing the average temperature of water in the water heater.

10. The method of claim 6, wherein:

presetting a plurality of offsets includes incrementing the first preset offset by a predetermined offset adjustment to define the at least one alternate offset.

generating a heat call facilitates reducing the average temperature of water in the water heater; and

the method further comprises;

detecting rate of change of temperature of the water; and

overriding the at least one alternate offset.

11. The method of claim 6, wherein the water heater is a gas based water heater.

12. The method of claim 6, wherein the water heater is an electric based water heater.